3. The diagonal of a square is equal to the side of an equilateral triangle. If the area of the square is 15?3 sq cm, what is the area of the equilateral triangle?
7. In ?PQR, S and T are points on side PQ and PR respectively. ST is parallel to QR. If lengths of PS, SQ and PR are 6 cm, 9 cm and 12.5 cm respectively, what is the length of TR?
9. In a triangle the length of the side opposite the angle which measures 60° is 6?3 cm. What is the length of the side opposite to the angle which measures 90°?
10. If a cone of radius 3.5 cm and height 9.6 cm is melted and constructed into a cylinder of the same radius, what will be the height of this cylinder? (Take ? = 22/7)